I used a wire harness out of a 94 Burb to make my harness for my 94 pickup, which happened to not be wired for power mirrors. The mirror wiring is within the main wire harness that goes across under the dash. The only way to access this wire harness is to pull the dash, and strip the wires out of the main harness.
It is a lot of work to get a harness for the mirrors. I did this because I had literally no money for buying new parts, my time was readily available and cheap and I needed something to occupy my time, and junkyard wire harnesses are very cheap if you pull them yourself. I also was being a bit anal about wiring in my new mirrors. I wanted them installed as close to what factory did as possible.
My recommendation would be to go to a junkyard and get the correct pigtails and both door harnesses, and then make your own harness for going across the vehicle. The "new" harness can be run under the carpet, up under the go pedal and heater. For powering the new mirrors I connected to stock locations on the convenience center as near as what I could possibly tell were stock.
I did make a few rough hand drawn diagrams and notes of what I did if you decide to go this route.
By the way, I love this line in your sig line. "An armed man is a citizen. An unarmed man is a subject.."
Don